Development of an EELS-MBE-ARPES System for Studying Collective Excitations in Quantum Materials
Abstract
Bosonic collective modes play a pivotal role in quantum materials they provide the pairing glue in all superconductors, give rise to new broken symmetry states such as charge and-or spin density waves, and can couple strongly to electrons to form new kinds of quasiparticles such as polarons. Despite their central importance in modern electronic and magnetic materials, experimental probes for measuring these collective modes simultaneously with both high energy and momentum resolution are lacking. In this proposal, we will develop and complete a state-of-the- art, momentum-resolved reflection electron energy loss spectroscopy (MR-EELS) system which will be fully integrated with an angle-resolved photoemission spectroscopy (ARPES) system, which will provide new insights into quantum materials by simultaneously revealing both their collective charge excitations (MR-EELS) as well as single-particle excitations (ARPES) with high energy and momentum resolution. We will employ this system to investigate charge density waves and electron-phonon coupling in unconventional superconductors such as hybrid interfacial monolayers of FeSe - SrTiO3, nickelates, and cuprates, as well as exciton dispersion and plasmons in two-dimensional van der Waals materials including MoS2 and WS2. This experimental system will have a number of key advantages, including - 1) its integration with an ARPES system to simultaneously measure both the energy- and momentum-resolved collective modes, as well as single particle excitations; 2) the use of an angular-multiplexing electron analyzer to collect hundreds of angular channels simultaneously, greatly increasing the data acquisition efficiency and momentum resolution; 3) its integration with an molecular beam epitaxy (MBE) growth chamber, allowing us to investigate a wide variety of thin films and heterostructures not usually accessible by MR-EELS. Developing an integrated EELS-ARPES-MBE system to investigate collective and single-particle excitations in a wide variety quantum materials will provide key insights into a broad range of phenomena in quantum materials with DoD-relevant electronic and magnetic properties, such as high-temperature superconductivity and exciton condensates.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310161
Entities
People
- Kyle Shen
Organizations
- Air Force Office of Scientific Research
- Cornell University
- United States Air Force